It is very difficult to perfectly align a telescope by only using the internal scope and positioning Polaris, and the tracking will drift over time leading to star trails. The declination drift technique below will give a much more accurate alignment and may be sufficient for taking data for exposures of a few minutes. However, there is a separate guide camera (G0 Moravian) which takes light from the edge of the field via an off axis prism adapter. The SIPS software takes a bright star in this image and guides the telescope automatically, keeping the star in the same position by sending control signals back to the mount. Read the SIPS V2 manual (on the Moravian website). If you want to try an alternative guiding software to SIPS, try PHD2: http://openphdguiding.org/. You can always resort to using a more accurate polar alignment method as detailed below. As a very last resort, you can take many short ~30 second exposures and stack them with deepskystacker.
- Take a one minute exposure with the ccd camera on its highest resolution. You will probably see that the stars drift slightly across the image. The autoguider will correct for this drift by searching for bright stars and guiding the mount keeping the star fixed in place
- Connect the white ‘telephone rj12’ guide control cable from the autoguide camera to the mount
- Attach the USB cable from the laptop to this camera, add this G0 camera as an autoguider in the tools menu of SIPS
- Under the guide menu, select the G0 camera and set an exposure time for ~second and a delay of ~second. (You may need to rotate the camera and guider to find a bright star in the field of view, if you do this then any flat fields you have taken will need to be taken again.) You may need to fine-tune the parameters, read the SIPS manual. In the guide window the software will detect stars and put green circles around them. Once you have a stable bright star in the guider view you will be ready to initialise auto-guiding.
- Under telescope control select ascom driver, then select takahashi mount
- Stop the guide exposures, click autoguide under the autoguide menu.
- The software will guide the telescope by keeping the brightest star in a fixed position. Take another ~one minute exposure with the main camera – if your stars are points of light rather than short trails of light then you have succeeded and you are now ready to take data! Congratulations!!